A wide variety of arrangements is presently known for providing interconnection between electrical contacts situated in a PCB with the leads or pins of an electronic package, typically a dual-in-line package (DIP) or other type of integrated circuit (IC) chip with supporting carrier. In a first such prior art approach, a base receives the DIP and has contacts therein which both engage the DIP leads interiorly of the base and extend outwardly of the base undersurface to seat in the PCB contacts. This approach is seen in U.S. Pat. No. 4,116,519.
So-called "stacking" of DIPs, a measure of current interest in the conservation of PCB real estate whereby plural electronic packages are disposed in tandem above the PCB, is accommodated in U.S. Pat. No. 4,116,519 interconnect scheme, since the base and its contacts are of sufficient height above the PCB to receive plural packages and to engage the leads of each package in parallel circuit arrangement. The U.S. Pat. No. 4,116,519 patent base contacts are, however, of flat blade configuration throughout their longitudinal extent and are disposed contiguously with the base sidewalls. Accordingly, the base contacts are immobilized and hence are passive during DIP insertion, the electrical contact resistance and the DIP retention force in the assembly thus being entirely dependent upon spring force arising from flexing of the DIP leads against the base contacts.
In a second approach akin to that of U.S. Pat. No. 4,116,519, and shown in U.S. Pat. No. 4,116,518, the base is provided in "clothes pin" fashion with a compression spring forcing closure of the base onto the DIP leads. The base again includes contacts immobilized therein and passive during asembly, as in the U.S. Pat. No. 4,116,519 approach. Electrical contact resistance is thus again derived from flexing of the DIP leads against the base contacts upon closure of the base onto the DIP leads.
While both such first and second prior art approaches are structurally simpler than other approaches in the prior art which either require plural sets of base contacts for accommodating the stacking of plural electronic packages or the interfitting of DIP leads of each package with those of another package and then with base contacts, a shortcoming common to known simplified approaches, as alluded to above, resides in their dependence upon the flexing and the flexure strength of the DIP leads for establishing assembly electrical contact resistance and retention force for containment of the DIPs in the assembly. Nor is the situation abetted by customary removal and reinsertion of the packages wherein it becomes necessary to re-deflect the previously bent DIP leads to render them suitable for re-flexing upon reinsertion. Clearly, the structurally simpler known approaches rely upon an operational capability of DIP package leads, i.e., flexure strength, not part of the design specifications thereof.